Traditional audio output devices for generating a surround sound effect include arrangements of 5.1 channels, 7.1 channels, 9.1 channels and etc. The setting of these channels may lead to excellent two-dimensional sound effects in a space but can't simulate full audio atmosphere created by a real object moving in a three-dimension space. Currently, except for using conventional surround sound channels, some movie theaters also add channel arrays on ceilings to better present sound contents of movies, so as to improve audiences' telepresence.
However, it's unlikely to equip extra channel arrays on ceilings of ordinary household rooms as in the movie theaters. Instead, via using audio output devices capable of upwardly firing sounds to ceilings, sounds are reflected to audiences, making users sense a three-dimensional sound effect. Nevertheless, each household room has a different environmental condition constructing an audio-visual space, such as volume, height of the audio-visual room or materials of the ceiling. Audio output devices currently available on the market have no way to fit themselves to different household environmental conditions. It turns out that the audio output devices can't demonstrate a default three-dimensional sound effect. That is, when the household environmental condition does not confirm to the environmental condition estimated at the time of designing the audio output devices, the household environmental conditions will diminish the full audio atmosphere.